An imprint technique is a technique of forming a fine pattern on a substrate by shaping an imprint material applied on a substrate with a mold. For example, a photocuring technique is one of such imprint techniques. In an imprint technique that employs a photocuring technique, an imprint material (photocurable resin) is first supplied to a shot, which is an imprint region, on a substrate. The imprint material is irradiated with light in a state in which a pattern in a mold is pressed against the imprint material, and the imprint material is thus cured. The mold is released from the cured resin, and thus a pattern made of resin is formed on the substrate.
In order to press a pattern in a mold against an imprint material on a substrate, the substrate and the mold need to be positioned relative to each other with high accuracy. For positioning a substrate and a mold relative to each other in an imprint apparatus, a so-called die-by-die method is known in which the positioning is achieved by detecting a mark formed on the mold and a mark formed in each shot on the substrate.
PTL 1 discloses an imprint apparatus provided with a detector that detects a positioning mark formed on each of a mold and a substrate and obtains the position in the X-direction and the position in the Y-direction on the substrate surface. Specifically, an X mark for detecting the position in the X-direction and a Y mark for detecting the position in the Y-direction are both illuminated, and light beams from the two marks are imaged by a single image sensor.
With the detector described in PTL 1, an unwanted light beam scattered, for example, by an edge of a positioning mark may be generated, and the unwanted light beam may reach the image sensor. Thus, the unwanted light beam may result in noise in the detection light beam from the mark, and the accuracy in measuring the position of the mark may be reduced.